Although not limited thereto, the invention is particularly applicable to the formation of knockdown reusable containers and enclosures formed of panels and pieces of fibrous material such as a multi-ply corrugated board, commonly referred to in the trade as tri-wall.
Panel interconnecting systems are well known, especially for the interconnection of panels along end corners or edges of rectangular containers where the panels extend from each other, usually at angles of 90.degree., examples of which are shown in my prior U.S. Pat. No. 4,139,113, issued Feb. 13, 1979 and in the patents and application referred to above of which this application is a continuation-in-part. My prior U.S. Pat. No. 4,584,806 discloses a system for interconnecting panels wherein the panels are abutted to one another and the joint between the panels is at an angle of from 180.degree. to 90.degree. or even less. In my prior U.S. Pat. No. 4,796,392 and in my application Ser. No. 07/293,828, which will issue as U.S. Pat. No. 4,914,874 on Apr. 10, 1990, a system is disclosed in which a side of one panel overlaps the end edge of an abutting panel. The connection systems just described are best adapted for use in the manufacture of reusable knockdown containers where the panels are formed of wood or other relatively rigid and durable material.
One of the important objectives of the present invention is the formation of reusable knockdown containers incorporating a novel form of spring clip and connector plate fastening system for interconnecting panels and pieces, wherein the container is made up of panels and pieces of a less durable and less rigid construction.
A still further objective of the invention is a provision of a releasable and reusable panel fastening system for attachment to container panels not well adapted for fastening with conventional fasteners. More particular, it is an objective of the invention to avoid the need for nails, screws, rivets or the like for fastening the plate components to the panels and pieces.
A related objective of the invention is the use of panel fastening means comprised of plate-like components which are well adapted to be adhesively secured to the panels which are to be interconnected.
A still further objective of my invention is the provision of a novel container system which facilitates side loading of containers formed of multiple panels and joined together according to the invention.
The above and other objectives of my invention are achieved by a fastening system which comprises paired plate-like components having apertures, the components being mounted adjacent to the edges of panels or planar surface which are in overlapping relationship to one another. The fastening system further comprises resilient spring clips which include a pair of oppositely extending spring arms, one of which has an end hook portion adapted to fit over the side edge of the aperture in one plate-like component and the other having a detent end portion dimensioned to fit within the aperture of the other plate-like component. The first plate-like component formed according to the invention is provided with a raised retainer flange which is disposed to overlap the side edge of the other panel, thereby preventing lateral separation of the overlapping panel portions.
According to a further aspect of the invention, the plate-like components are constructed so as to provide clearance between the edge surfaces of the apertures and the panel surfaces for the end hook and detent portions of the spring arms so as to avoid scarring, gouging or penetration of the panel surface when the spring clips are in position.
According to still another aspect of the invention, the plate-like components are formed with downwardly directed pointed darts or lances which provide limited penetration of the surface of the panel to which they are joined. When the plate-like components are intended to be adhesively secured to the panels, the darts position the plate-like components during the set-up of the adhesive. Still further, although the adhesives have excellent tensile properties, they may be weak in shear strength and the darts serve to resist any forces which may act to shear a plate from the surface to which it is secured.
The fastening systems of the present invention may be used in combination with the fastening systems disclosed and claimed in the cases above identified, as for example where a container formed partially of wooden panels and partially of corrugated panels may be desirable. It is also to be understood that the fastening systems of the present invention are applicable to a wide variety of structures incorporating interconnected panels and the term container herein is not to be used in a limiting sense .